<template>
  <div class="upload-box">
    <el-upload
      v-model:file-list="_fileList"
      action="#"
      list-type="picture-card"
      :class="['upload', self_disabled ? 'disabled' : '', drag ? 'no-border' : '']"
      :multiple="true"
      :disabled="self_disabled"
      :limit="limit"
      :http-request="handleHttpUpload"
      :before-upload="beforeUpload"
      :on-exceed="handleExceed"
      :on-success="uploadSuccess"
      :on-error="uploadError"
      :drag="drag"
      :accept="fileType.join(',')"
    >
      <div class="upload-empty">
        <slot name="empty">
          <el-icon><Plus /></el-icon>
          <!-- <span>请上传图片</span> -->
        </slot>
      </div>
      <template #file="{ file }">
        <img :src="file.url" class="upload-image" />
        <div class="upload-handle" @click.stop>
          <div class="handle-icon" @click="handlePictureCardPreview(file)">
            <el-icon><ZoomIn /></el-icon>
            <span>查看</span>
          </div>
          <div v-if="!self_disabled" class="handle-icon" @click="handleRemove(file)">
            <el-icon><Delete /></el-icon>
            <span>删除</span>
          </div>
        </div>
      </template>
    </el-upload>
    <div class="el-upload__tip">
      <slot name="tip"></slot>
    </div>
    <el-image-viewer v-if="imgViewVisible" :url-list="[viewImageUrl]" @close="imgViewVisible = false" />
  </div>
</template>

<script setup lang="ts" name="UploadImgs">
  import { ref, computed, inject, watch } from "vue"
  import { Plus } from "@element-plus/icons-vue"
  import { uploadImg } from "@/api/modules/upload"
  import type { UploadProps, UploadFile, UploadUserFile, UploadRequestOptions } from "element-plus"
  import { ElNotification, formContextKey, formItemContextKey } from "element-plus"

  interface UploadFileProps {
    fileList: UploadUserFile[]
    api?: (params: any) => Promise<any> // 上传图片的 api 方法，一般项目上传都是同一个 api 方法，在组件里直接引入即可 ==> 非必传
    drag?: boolean // 是否支持拖拽上传 ==> 非必传（默认为 true）
    disabled?: boolean // 是否禁用上传组件 ==> 非必传（默认为 false）
    limit?: number // 最大图片上传数 ==> 非必传（默认为 5张）
    fileSize?: number // 图片大小限制 ==> 非必传（默认为 5M）
    fileType?: File.ImageMimeType[] // 图片类型限制 ==> 非必传（默认为 ["image/jpeg", "image/png", "image/gif"]）
    height?: string // 组件高度 ==> 非必传（默认为 150px）
    width?: string // 组件宽度 ==> 非必传（默认为 150px）
    borderRadius?: string // 组件边框圆角 ==> 非必传（默认为 8px）
  }

  const props = withDefaults(defineProps<UploadFileProps>(), {
    fileList: () => [],
    drag: true,
    disabled: false,
    limit: 5,
    fileSize: 5,
    fileType: () => ["image/jpeg", "image/png", "image/gif"],
    height: "150px",
    width: "150px",
    borderRadius: "8px"
  })

  // 获取 el-form 组件上下文
  const formContext = inject(formContextKey, void 0)
  // 获取 el-form-item 组件上下文
  const formItemContext = inject(formItemContextKey, void 0)
  // 判断是否禁用上传和删除
  const self_disabled = computed(() => {
    return props.disabled || formContext?.disabled
  })

  const _fileList = ref<UploadUserFile[]>(props.fileList)

  // 监听 props.fileList 列表默认值改变
  watch(
    () => props.fileList,
    (n: UploadUserFile[]) => {
      _fileList.value = n
    }
  )

  /**
   * @description 文件上传之前判断
   * @param rawFile 选择的文件
   * */
  const beforeUpload: UploadProps["beforeUpload"] = (rawFile) => {
    const imgSize = rawFile.size / 1024 / 1024 < props.fileSize
    const imgType = props.fileType.includes(rawFile.type as File.ImageMimeType)
    if (!imgType)
      ElNotification({
        title: "温馨提示",
        message: "上传图片不符合所需的格式！",
        type: "warning"
      })
    if (!imgSize)
      setTimeout(() => {
        ElNotification({
          title: "温馨提示",
          message: `上传图片大小不能超过 ${props.fileSize}M！`,
          type: "warning"
        })
      }, 0)
    return imgType && imgSize
  }

  /**
   * @description 图片上传
   * @param options upload 所有配置项
   * */
  const handleHttpUpload = async (options: UploadRequestOptions) => {
    let formData = new FormData()
    formData.append("file", options.file)
    try {
      const api = props.api ?? uploadImg
      const { data } = await api(formData)
      options.onSuccess(data)
    } catch (error) {
      options.onError(error as any)
    }
  }

  /**
   * @description 图片上传成功
   * @param response 上传响应结果
   * @param uploadFile 上传的文件
   * */
  interface UploadEmits {
    (e: "update:fileList", value: UploadUserFile[]): void
  }
  const emit = defineEmits<UploadEmits>()
  const uploadSuccess = (response: { fileUrl: string } | undefined, uploadFile: UploadFile) => {
    if (!response) return
    uploadFile.url = response.fileUrl
    emit("update:fileList", _fileList.value)
    // 调用 el-form 内部的校验方法（可自动校验）
    formItemContext?.prop && formContext?.validateField([formItemContext.prop as string])
    ElNotification({
      title: "温馨提示",
      message: "图片上传成功！",
      type: "success"
    })
  }

  /**
   * @description 删除图片
   * @param file 删除的文件
   * */
  const handleRemove = (file: UploadFile) => {
    _fileList.value = _fileList.value.filter((item) => item.url !== file.url || item.name !== file.name)
    emit("update:fileList", _fileList.value)
  }

  /**
   * @description 图片上传错误
   * */
  const uploadError = () => {
    ElNotification({
      title: "温馨提示",
      message: "图片上传失败，请您重新上传！",
      type: "error"
    })
  }

  /**
   * @description 文件数超出
   * */
  const handleExceed = () => {
    ElNotification({
      title: "温馨提示",
      message: `当前最多只能上传 ${props.limit} 张图片，请移除后上传！`,
      type: "warning"
    })
  }

  /**
   * @description 图片预览
   * @param file 预览的文件
   * */
  const viewImageUrl = ref("")
  const imgViewVisible = ref(false)
  const handlePictureCardPreview: UploadProps["onPreview"] = (file) => {
    viewImageUrl.value = file.url!
    imgViewVisible.value = true
  }
</script>

<style scoped lang="scss">
  .is-error {
    .upload {
      :deep(.el-upload--picture-card),
      :deep(.el-upload-dragger) {
        border: 1px dashed var(--el-color-danger) !important;
        &:hover {
          border-color: var(--el-color-primary) !important;
        }
      }
    }
  }
  :deep(.disabled) {
    .el-upload--picture-card,
    .el-upload-dragger {
      cursor: not-allowed;
      background: var(--el-disabled-bg-color) !important;
      border: 1px dashed var(--el-border-color-darker);
      &:hover {
        border-color: var(--el-border-color-darker) !important;
      }
    }
  }
  .upload-box {
    .no-border {
      :deep(.el-upload--picture-card) {
        border: none !important;
      }
    }
    :deep(.upload) {
      .el-upload-dragger {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
        height: 100%;
        padding: 0;
        overflow: hidden;
        border: 1px dashed var(--el-border-color-darker);
        border-radius: v-bind(borderRadius);
        &:hover {
          border: 1px dashed var(--el-color-primary);
        }
      }
      .el-upload-dragger.is-dragover {
        background-color: var(--el-color-primary-light-9);
        border: 2px dashed var(--el-color-primary) !important;
      }
      .el-upload-list__item,
      .el-upload--picture-card {
        width: v-bind(width);
        height: v-bind(height);
        background-color: transparent;
        border-radius: v-bind(borderRadius);
      }
      .upload-image {
        width: 100%;
        height: 100%;
        object-fit: contain;
      }
      .upload-handle {
        position: absolute;
        top: 0;
        right: 0;
        box-sizing: border-box;
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
        height: 100%;
        cursor: pointer;
        background: rgb(0 0 0 / 60%);
        opacity: 0;
        transition: var(--el-transition-duration-fast);
        .handle-icon {
          display: flex;
          flex-direction: column;
          align-items: center;
          justify-content: center;
          padding: 0 6%;
          color: aliceblue;
          .el-icon {
            margin-bottom: 15%;
            font-size: 140%;
          }
          span {
            font-size: 100%;
          }
        }
      }
      .el-upload-list__item {
        &:hover {
          .upload-handle {
            opacity: 1;
          }
        }
      }
      .upload-empty {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 12px;
        line-height: 30px;
        color: var(--el-color-info);
        .el-icon {
          font-size: 28px;
          color: var(--el-text-color-secondary);
        }
      }
    }
    .el-upload__tip {
      line-height: 15px;
      text-align: center;
    }
  }
</style>
